I assume therefore I am (human)

I assume therefore I am (human)

By Pati Anderson

I am a small person. Not just the below-average-height "cute" kind of small. I am the disarmingly, double-take inducing, offered-a-kids-menu-while-visibly-pregnant kind of small. While I firmly deny the existence of any grey hairs (they're just really blond), I do not entertain any sort of notion that my face is that of a 16 year old anymore. Yet, I get mistaken for one all the time. As a teenager I used to change the way I dressed and did my makeup, even the way I held myself and spoke, to try to mitigate being mistaken for a child. Eventually I accepted the fact that it wasn’t those details that people noticed when making assumptions about my age - it was much simpler and much more out of my control than that. I am small. Children are small.

The thing about being quite different from the norm in some way is that you get to witness people making false assumptions and acting off their "first impressions" in perhaps a more drastic way then otherwise seen in day-to-day life. The thing about being a human factors engineer is that we get to see that very same phenomenon all the time in our studies.

Imagine a sponsor designing a beautiful nasal spray device and plastering the word "nasal" all over their device and never dreaming for a moment that anyone would confuse their nasal spray device for something else. Yet then in the observation room they struggle to pick their jaws up off the floor as they watch participant after participant attempt to inject, drink, or otherwise use their device in all sorts of unintended ways. What causes this behavior?

When someone has to use a device they are unfamiliar with, they often rely on their preconceived assumptions about how they think the device ought to work, along with their first impression of how the device seems to work. The challenge for the designer is to figure out how to combat those unpredictable assumptions and first impressions with limited knowledge about what specific details the user is latching onto in order to create those assumptions and first impressions.

Sometimes these assumptions sprout from things that have nothing to do with the device itself; for example they might be influenced by the situation or indication for which the device is meant. If someone expects that a certain medication is injected because that is all they have ever known about, they might be more inclined to assume this new device is also injected unless something about the device forcibly intervenes to change their preexisting mental model.

Sometimes these first impressions are very much related to some aspect of the device, but simply go completely unforeseen by the designers until the unintended use shows up in usability studies. For example, a participant may think the nasal spray looks like an injector, nothing about the device causes them to question the method of drug delivery and want to look for more information, and incidentally the "nasal" labeling goes unnoticed and therefore isn't factored into the generation of that crucial first impression, all culminating in the unintended "injection" of the nasal spray.

What can a designer do to challenge or influence these assumptions and first impressions? The first step is to identify them. Typically these issues come as a shock to the designers, because it is hard to understand the perspective others have about your device when you are too close to it yourself (think about the not-16-anymore-face and the definitely-just-blond-grey-hairs). The best way to identify any kind of unintended use is by running formative usability studies as early as possible, and iteratively as your design develops.

The next step is to come up with ways to influence users' assumptions and mold their first impressions. This may be through labeling, device shape/appearance, or even training (think about the makeup and posture). Any mitigations you devise should of course be tested, but be prepared to learn that changes to labeling and training may have minimal effects. The onus is on the sponsor to iteratively design their device to be the safest possible version they can reasonably design. However, I do believe there are instances when people have deeply ingrained assumptions about medical devices that can only be changed at a societal level through exposure over time (for example, repeatedly seeing on TV or in ads or from friends and family that a certain medication can be injected but also can be inhaled).

Unfortunately for me, I think children will always be small and adults will always be tall, and I'll be happily battling false assumptions over here somewhere-in-between.